The del statement is Python's primary mechanism for unbinding a name from an object, effectively deleting the variable. The most direct syntax is del coursename. The syntax del(coursename) is also valid, as the parentheses simply group the target name. The globals() built-in function returns a dictionary representing the current global symbol table. Therefore, one can manipulate this dictionary directly to remove a variable, making del globals()['coursename'] a correct, albeit less common, method for deleting a global variable. These three methods successfully remove the coursename variable from the global scope.

A. remove is not a Python keyword for deleting variables; it is a method for mutable collection types like lists and sets.

C. rm is a command-line utility for removing files in Unix-like systems, not a valid statement or keyword in the Python language.

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1. Official Python Documentation, The Python Language Reference:

Section 7.4. The del statement: This section explicitly defines the syntax and semantics of the del statement for removing name bindings. It states, "Deletion of a name removes the binding of that name from the local or global namespace...". The syntax shown includes del targetlist, where a target can be a simple name like coursename.

URL: https://docs.python.org/3/reference/simplestmts.html#the-del-statement

2. Official Python Documentation, The Python Standard Library:

Built-in Functions, globals(): The documentation for globals() states, "Return a dictionary representing the current global symbol table. This is always the dictionary of the current module...". Modifying this returned dictionary, such as by deleting a key, directly modifies the global namespace.

URL: https://docs.python.org/3/library/functions.html#globals

3. MIT OpenCourseWare, 6.0001 Introduction to Computer Science and Programming in Python:

Lecture 5 Notes: In discussions on scopes and namespaces, the course materials explain that variables exist within specific namespaces (local, global, etc.). The del statement is introduced as the mechanism to remove a name from a namespace. The concept of the global namespace being accessible via globals() aligns with using dictionary operations on its return value.

Reference: MIT OCW 6.0001, Fall 2016, Lecture 5: Tuples, Lists, Aliasing, Mutability, Cloning. (The principles of namespaces and variable management are foundational in this lecture).